1. Field of the Invention
This invention relates, in general, to the class of inventions having as a primary object the savings of energy derived from fossil or fissile fuels and in particular to electrical energy savings apparatus designed for illumination.
2. Description of the Prior Art
The unbridled use of electrical energy is no longer possible. The United States of America is already too dependent upon our foreign neighbors for our supply of oil. The use of our abundant reserves of coal is not presently feasible because the hazards produced by pollution necessitate that it be made clean prior to burning and pollution-free coal is not as economical as the present high price of gas or oil. Nuclear power is similarly disadvantageous because of the radioactive waste disposal problem, which seemingly is unsolvable. New and efficient means to conserve energy must be discovered, invented and implemented now. The instant invention and the apparatus disclosed herein has been shown to be an effective means to conserve energy. In addition, its implementation will result in a significant cost saving to both business and the consumer as well as the government of the United States of America, the governments of the individual states and their political subdivisions.
During the early stages of civilization, natural illumination from solar energy was, of course, the only source of light that was available. The discovery or invention of fire and the illumination produced thereby aided man in his quest to light up the darkness which existed during the non-daylight hours or during daylight hours in areas where natural illumination did not sufficiently penetrate. The invention of electricity coupled with the inventions of the various types of light bulbs seemed to answer man's problem of achieving adequate illumination. For reasons detailed above, the present energy shortage and man's increasing need for energy has caused the problems associated with adequate illumination to resurface. The main problem being the supplying of adequate illumination while conserving as much energy as possible.
Modern architects have recognized and addressed the need to conserve energy in the design of new office buildings. For example, many new buildings utilize the heat produced by the people occupying the building and the heat produced by the illuminating system to provide heat for the building in the winter months. Then too, in southern regions, architects use cool-burning light fixtures to decrease the demand on air-conditioning within the building. Window coatings and even glass have been invented and used to either reflect or absorb the sun's thermal energy depending on whether it is desired to heat or cool the building. However, very little has been accomplished in the field of illumination as regards utilizing the combination of natural light and artificial light to decrease the cost of artificial illumination and to conserve energy.
A simple survey of old buildings as might be used for offices or new, modern buildings will disclose that no light-control devices or apparatus are utilized, notwithstanding the abundant illumination available from natural sources. One reason attributable to this non-use is because there is no prior art device or apparatus which is sufficiently sophisticated so as to be capable of effectively being utilized for this purpose.
Illumination control systems have, of course, been disclosed and developed in the past, but these are primarily concerned with turning a light fixture on or off. The invention of Dubot, et al in U.S. Pat. No. 3,961,183, issued June 1, 1976, is an example of such a device. There, Dubot, et al, disclosed a light responsive electric switch utilizing a motor having stepped-down gearing to activate street lighting. The invention of Bolhuis, in U.S. Pat. No. 3,863,104, Jan., 1975, is another such example. The Bolhuis invention being concerned with assuring a minimum amount of light from tunnel lights in the event that a failure occurs in the main apparatus turning the lights on.
The invention of Dewan in U.S. Pat. No. 2,199,394, May, 1940, LIGHT CONTROL SYSTEM tends to address the problem of saving energy by using a combination of natural light and artificial light in a structure. However, the relatively simplistic but direct approach of Dewan falls short of the need for a reliable, economical, precise system. Also, a main disadvantage of Dewan's invention is that it would be sensitive to phenomena such a lightning. Dewan uses an amplified signal from a photocell to activate a switch, which is assisted by an electromagnet, and which upon making contact activates a solenoid which, in turn, activates an electro-mechanical switch and activates (or deactivates) a light. By using a plurality of such solenoids and electro-mechanical switches, in conjunction with preset, increasing output levels of the photocell, Dewan increases the amount of artificial light when the light available from the natural sources decreases.
Should the photocell of Dewan's invention be suddenly be exposed to lightning, then most or all of the artificial lights would be momentarily turned off. They would, of course, go back on; but, during a protracted storm having a large amount of lightning, such results would be intolerable inasmuch as lights continuously turning on and off would seriously disrupt the organized workings of a modern office building. Another disadvantage of Dewan's invention is the relative unreliability of the relays and the electro-mechanical switches.
A prior art invention which addresses itself to the above-stated problems is that of the previously mentioned patent application of Lester J. Owens. Owens discloses apparatus for combining solar light with artificial light to maintain a desired level of illumination within a structure. He uses a light sensor to control a bi-directional clock motor having mercury switches thereon to increasingly (or decreasingly) activate a plurality of lights associated therewith. Owen's solution to making the apparatus insensitive to lightning, is the inherent slow response time of the motor due to its slow rotational speed. When the motor rotates, a plate having mercury switches thereon also rotates. In this manner, the mercury switches progressively close and lights connected to the switches progressively turn on. Thus, although Owens directly addresses the problem, he still relies upon mechanical devices to achieve the result.
In conclusion, the prior art does not disclose any apparatus or system which is economical, reliable or precise.